Automatic welding wire feed adjuster

ABSTRACT

An automatic wire feed adjuster, including a feeding mechanism including a pair of rollers that feeds a wire therebetween, a tension controller that adjusts a tension between the pair of rollers, a wire speed sensor that measures a fed speed of the wire after exiting the feeding mechanism, and a control circuit that compares a driven speed of the wire with the fed speed of the wire, and that decides whether to instruct the tension controller to adjust the tension between the pair of rollers.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Devices, systems, and methods consistent with the invention relate to anautomatic feed adjuster.

2. Description of the Related Art

In the related art, there are various types of welding processes,including processes which utilize a continuous wire feed as a weldingelectrode.

A diagrammatical representation of such a related art continuous wirefeed welding process is illustrated in FIG. 1. In FIG. 1, a weldingsystem 1 includes a control circuit 10, a power source 20, a motor 12,and spool 30. Spool 30 contains wire 35 spooled thereon. Motor 12 drivesopposing rollers 14 to take up wire 35 from spool 30 and send it to gun22. The operator utilizes gun 22 to form a weld on workpiece 40. As theweld is formed on workpiece 40, wire 35 is consumed at gun 22, and isreplaced by feeding more wire 35 to gun 22 by action of motor 12 androllers 14 at a constant rate.

Different types of wires 35 are available for different weldingapplications. The selection of a particular type of wire depends onseveral factors, including, e.g., the type of material being welded, theweld design, material surface conditions, quality concerns, and processvariation concerns. Due to these considerations, the different types ofwires have widely varying diameters.

As mentioned above, in the system illustrated in FIG. 1, wire 35 is fedto gun 22 at a constant rate during a welding operation. This rate isset by the operator via a variable knob on control circuit 10 before thewelding operation begins. Different rates are appropriate for differentwelding applications. For example, a thicker material to be welded mayrequire a faster feed, while a thinner material may require a slowerspeed to avoid burn-through.

In order to provide the desired feed rate, an amount of tension betweenrollers 14 is also adjustable by the operator, before the weldingoperation begins. The term tension is broadly utilized in this contextto represent both a “tension” force acting on each roller 14 in adirection toward the other (e.g., as created by a spring memberconnecting the two rollers 14) and as a “pressure” forcing the rollers14 toward each other (e.g., as created by spring members on oppositesides of the two rollers 14). This tension between rollers 14 acts todraw wire 35 off of spool 30, and feed wire 35 toward gun 22. Theadjustment is typically provided by a small thumb-wheel or otheradjustment mechanism.

The tension between rollers 14 is set in view of the diameter of thewire 35, and remains constant during the welding operation.Unfortunately, if the tension between rollers 14 is set too high, therollers 14 will deform the wire 35 as it passes therethrough. Such adeformed wire 35 can jam gun 22. On the other hand, if the pressurebetween rollers 14 is set too low, wire 35 will be fed to gun 22 at anerratic rate, which results in an erratic welding arc and poor weldquality.

Further, even if the tension is set properly on a first section of wire35, there is inherent variability in the diameter of wire 35 due to suchfactors as manufacturing process variation and/or damage during shipmentor storage. In other words, wire 35 may not have a constant diameteralong its length. Thus, as wire 35 is fed to gun 22 through rollers 14,the tension set before the welding operation (in view of a beginningdiameter of wire 35) might become inappropriate, and wire 35 might beginto deform or be erratically fed, as described above.

The above problems demand an improvement in the related art system.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, there is provided an automatic feedtension adjuster that overcomes the problems of the related art.

In another aspect of the invention, there is provided an automatic wirefeed adjuster, including a feeding mechanism comprising a pair ofrollers that feeds a wire therebetween, a tension controller thatadjusts a tension between the pair of rollers, a control circuit thatdecides whether to instruct the tension controller to adjust the tensionbetween the pair of rollers.

In another aspect of the invention, there is provided an automatic wirefeed adjuster, including a feeding mechanism including a pair of rollersthat feeds a wire therebetween, a tension controller that adjusts atension between the pair of rollers, a wire speed sensor that measures afed speed of the wire after exiting the feeding mechanism, and a controlcircuit that compares a driven speed of the wire with the fed speed ofthe wire, and that decides whether to instruct the tension controller toadjust the tension between the pair of rollers.

In another aspect of the invention, there is provided an automatic wirefeed adjuster, including a feeding mechanism for feeding a wiretherethrough by applying a force to the wire, a force adjuster thatadjusts the force applied to the wire, a control circuit that decideswhether to instruct the force adjuster to adjust the force applied tothe wire.

In another aspect of the invention, there is provided an automatic wirefeed adjuster, including a feeding mechanism for feeding a wiretherethrough by applying a force to the wire, a force adjuster thatadjusts the force applied to the wire, a wire speed sensor that measuresa fed speed of the wire after exiting the feeding mechanism, and acontrol circuit that compares a driven speed of the wire with the fedspeed of the wire, and that decides whether to instruct the forceadjuster to adjust the force applied to the wire.

In another aspect of the invention, there is provided a method ofadjusting a wire feed, including feeding a wire through a driven pair ofrollers having a tension therebetween, measuring a fed speed of the wireafter it exits from between the pair of rollers, and deciding whether toadjust the tension between the pair of rollers.

In another aspect of the invention, there is provided a method ofadjusting a wire feed, including feeding a wire through a driven pair ofrollers having a tension therebetween, measuring a fed speed of the wireafter it exits from between the pair of rollers, comparing a drivenspeed of the wire with the fed speed of the wire, and deciding whetherto adjust the tension between the pair of rollers.

In another aspect of the invention, there is provided a method ofadjusting a wire feed, including feeding a wire through a feedingmechanism that applies a force to the wire, measuring a fed speed of thewire after it exits from the feeding mechanism, and deciding whether toadjust the force applied to the wire.

In another aspect of the invention, there is provided a method ofadjusting a wire feed, including feeding a wire through a feedingmechanism that applies a force to the wire, measuring a fed speed of thewire after it exits from the feeding mechanism, comparing a driven speedof the wire with the fed speed of the wire, and deciding whether toadjust the force applied to the wire.

In another aspect of the invention, there is provided a control circuitthat decides whether to instruct a tension controller to adjust atension between a pair of rollers in a feeding mechanism that feeds awire therebetween.

In another aspect of the invention, there is provided a tensioncontroller that adjusts a tension between a pair of rollers in a feedingmechanism that feeds a wire therebetween in view of a comparison of adriven speed of the wire determined from the pair of rollers with thefed speed of the wire measured on the wire.

The above stated aspects, as well as other aspects, features andadvantages of the invention will become clear to those skilled in theart upon review of the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects of the invention will be more apparent bydescribing in detail exemplary embodiments of the invention withreference to the accompanying drawings, in which:

FIG. 1 illustrates a diagrammatic representation of a welding systemaccording to the related art; and

FIG. 2 illustrates a diagrammatic representation of a welding systemaccording to an embodiment of the invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the invention will now be described below byreference to the attached Figures. The described exemplary embodimentsare intended to assist the understanding of the invention, and are notintended to limit the scope of the invention in any way. Like referencenumerals refer to like elements throughout.

In an exemplary embodiment of the invention, an automatic feed adjusteris utilized to provide optimized wire feeding and welding.

More specifically, as shown in FIG. 2, welding system 101 includescontrol circuit 110, power source 120, motor 112, tension control 115,wire speed sensor 116, user/data interface 118, and spool 130. Spool 130contains wire 135 spooled thereon. Motor 112 drives opposing rollers 114to take up wire 135 from spool 130 and send it to gun 122. The operatorutilizes gun 122 to form a weld on workpiece 140. As the weld is formedon workpiece 140, wire 135 is consumed, and is replaced by motor 112.

User/data interface 118 provides an input for data regarding wire 135 tobe entered into welding system 101. This wire data may include anyparticular information regarding the wire 135, such as its diameter,length, configuration, manufacturer part number, internal part number,or any other physical, chemical or performance properties that may beuseful.

The user/data interface 118 may include, without limitation, anydigital, analog, or manual device whereby an operator can enter wiredata (e.g., a Graphical User Interface, a text based input system,adjustment knobs, sliders, etc.) or any device that reads wire data fromwire 135 or its packaging (e.g., a RFID) reader, magnetic or opticaldrive, bar code reader, etc.). Further, data regarding wire 135 may alsobe stored within welding system 101 for later use (or pre-stored beforeuse), and simply be accessed by the operator through user/data interface118.

Welding system 101 then utilizes wire data for wire 135 to initiallyadjust, and continuously control, the tension between rollers 114 (viatension control 115). More specifically, tension control 115 firstadjusts the tension between rollers 114 to a setting equal to an initialtension that is equal to a minimum amount of tension between rollers 114necessary to feed wire 135 to gun 122 without slipping. This initialminimum tension is determined according to the wire data (e.g., adiameter) of wire 135. The wire data may be input to welding system 101as discussed above.

Next, during the welding operation, as wire 135 is fed continuouslythrough rollers 114, the tension control operates to continuously adaptthe tension between rollers 114 to maintain a minimum amount of tensionbetween rollers 114 necessary to feed wire 135 to gun 122 withoutslipping. This operating minimum tension is determined by feedback datadelivered to control circuit 110 from motor 112 and wire speed sensor116, as described below.

The use of these minimum tensions avoids any erratic feeding of the wire135 due to a tension that is set too low, and any possible deformationof the wire 135 due to a tension that is set too high. Further, astension adjustments are accomplished automatically by tension control115, the possibility of operator error influencing the feeding of wire135 is drastically reduced.

As mentioned above, the operating minimum tension is determined byfeedback data. More specifically, when the welding system 101 is feedingwire 135 via motor 112 and opposing rollers 114, the control circuit 110obtains a first wire speed of the wire 135 by measuring the speed of themotor 112 and taking into account the diameters of rollers 114.Additionally, the control circuit 110 obtains a second wire speed fromwire speed sensor 116, which directly measures the speed of wire 135 asit passes thereby. Control circuit 110 then compares the first andsecond wire speeds. If the wire speeds are the same, no slipping of wire135 on opposing rollers 114 is occurring, and no tension adjustment isnecessary. Thus, the control circuit 110 does not instruct the tensioncontrol 115 to modify the tension of rollers 114.

However, if the first wire speed calculated from the motor speed ishigher than the second wire speed read from the wire sensor 118, thewire 135 is slipping on opposing rollers 114. Thus, control circuit 110will instruct the tension control 115 to increase the tension betweenopposing rollers 114 until the first and second wire speeds becomeequivalent (i.e., until the wire 135 stops slipping).

Control circuit 110 will continue to increase the tension betweenopposing rollers 114 until it reaches a maximum value. The maximum valuemay be set in view of many factors, including a point at which the wire135 will begin to deform because of the tension. This maximum value isdetermined according to the wire data (e.g., a diameter, type, size,etc.) of wire 135.

The sampling rate for determining the first and second wire speed is notlimited, but should be set to optimize the welding operation.

The wire speed sensor can be any sensor that is capable of providing therequired wire speed data, including, without limitation, electronic ormechanical sensors that contact or do not contact the wire 135. Whilethe wire speed sensor in FIG. 2 is positioned after rollers 114, sincethe wire is continuous, the speed sensor can be placed at any pointalong the length of wire 135.

Opposing rollers 114 are illustrated in this exemplary embodiment.However, opposing rollers are not required, and the invention is notlimited thereto. For example, the invention is equally applicable tosystem having more or less than two rollers, or to systems that useother driving concepts for wire 135 that create some kind of pressure onthe wire. This pressure can be adjusted similarly to the tensiondescribed in the exemplary embodiment.

Further, there is no limitation to the amount of rollers 114 that arepowered by motor 112. For example, one roller of the rollers 114 may bepowered, and one roller may be an unpowered following roller.

The term tension is broadly used in the context of this invention. Itmeans either a “tension” force acting on each roller in a directiontoward the other and as a “pressure” forcing the rollers toward eachother. This tension can be created by spring members, elastic members,levers, electric motors, or any other such device. The amount of tensionis adjustable by adjusting the pressure or tension exerted by thesedevices, which in turn adjusts the tension between the opposing rollers.The amount of pressure or tension exerted by the devices can becontrolled by the tension control 115, or other such component, viaelectrical or mechanical means.

As mentioned above, the exemplary embodiment utilizes wire data to setan initial tension equal to a minimum amount of tension between rollers114. However, the invention is not limited thereto, and the initialtension may be set at a point between the minimum and maximum tension.Thereafter, the tension control may operate to reduce the tension untilthe feedback data indicates that there is slipping of the wire, at whichpoint tension may again be increased according to the process describedabove.

Although FIG. 2 illustrates a single welding system 101 including spool130, motor 112, opposing rollers 114, tension controller 116 and wirespeed sensor 118, each of these elements may be independently provided,or grouped together in any desirable combination. For example, theroller 114 may be removably attached to a welding machine, located closeto the machine, or built into the machine, depending on a particularmanufacturer's style and type of machine. Further, the invention may beretrofitted to existing welding systems by adding the necessarycomponents.

The welding system described herein is applicable to any welding systemthat utilizes a wire feed.

While the invention has been particularly shown and described withreference to exemplary embodiments thereof, the invention is not limitedto these embodiments. It will be understood by those of ordinary skillin the art that various changes in form and details may be made thereinwithout departing from the spirit and scope of the invention as definedby the following claims.

1. An automatic wire feed adjuster, comprising: a feeding mechanismcomprising a pair of rollers that feeds a wire therebetween; a tensioncontroller that adjusts a tension between the pair of rollers; a controlcircuit that decides whether to instruct the tension controller toadjust the tension between the pair of rollers.
 2. An automatic wirefeed adjuster, comprising: a feeding mechanism comprising a pair ofrollers that feeds a wire therebetween; a tension controller thatadjusts a tension between the pair of rollers; a wire speed sensor thatmeasures a fed speed of the wire after exiting the feeding mechanism, acontrol circuit that compares a driven speed of the wire with the fedspeed of the wire, and that decides whether to instruct the tensioncontroller to adjust the tension between the pair of rollers.
 3. Theautomatic wire feed adjuster recited in claim 2, wherein the drivenspeed of the wire is calculated by taking into account the rotationalspeed and the diameter of at least one of the pair of rollers.
 4. Theautomatic wire feed adjuster recited in claim 2, wherein the controlcircuit increases the tension between the pair of rollers when thedriven speed of the wire is greater than the fed speed of the wire. 5.The automatic wire feed adjuster recited in claim 2, further comprisinga user interface for accepting wire data, wherein: the wire datacomprises a wire diameter; and the control circuit determines an initialtension between the pair of rollers, and a maximum tension between thepair of rollers, in view of the wire data.
 6. An automatic wire feedadjuster, comprising: a feeding mechanism for feeding a wiretherethrough by applying a force to the wire; a force adjuster thatadjusts the force applied to the wire; a control circuit that decideswhether to instruct the force adjuster to adjust the force applied tothe wire.
 7. An automatic wire feed adjuster, comprising: a feedingmechanism for feeding a wire therethrough by applying a force to thewire; a force adjuster that adjusts the force applied to the wire; awire speed sensor that measures a fed speed of the wire after exitingthe feeding mechanism, a control circuit that compares a driven speed ofthe wire with the fed speed of the wire, and that decides whether toinstruct the force adjuster to adjust the force applied to the wire. 8.The automatic wire feed adjuster recited in claim 8, wherein the drivenspeed of the wire is the speed of the wire within the feeding mechanism.9. The automatic wire feed adjuster recited in claim 8, wherein thecontrol circuit increases the force applied to the wire when the drivenspeed of the wire is greater than the fed speed of the wire.
 10. Theautomatic wire feed adjuster recited in claim 8, further comprising auser interface for accepting wire data, wherein: the wire data comprisesa wire diameter; and the control circuit determines an initial pressureapplied to the wire, and a maximum pressure applied to the wire, in viewof the wire data.
 11. A method of adjusting a wire feed, comprising:feeding a wire through a driven pair of rollers having a tensiontherebetween; measuring a fed speed of the wire after it exits frombetween the pair of rollers; deciding whether to adjust the tensionbetween the pair of rollers.
 12. A method of adjusting a wire feed,comprising: feeding a wire through a driven pair of rollers having atension therebetween; measuring a fed speed of the wire after it exitsfrom between the pair of rollers; comparing a driven speed of the wirewith the fed speed of the wire; and deciding whether to adjust thetension between the pair of rollers.
 13. The method of adjusting a wirefeed recited in claim 15, further comprising calculating the drivenspeed of the wire by taking into account the rotational speed and thediameter of at least one of the pair of rollers.
 14. The method ofadjusting a wire feed recited in claim 15, further comprising increasingthe tension between the pair of rollers when the driven speed of thewire is greater than the fed speed of the wire.
 15. The method ofadjusting a wire feed recited in claim 15, further comprising: enteringwire data via a user interface, wherein the wire data comprises a wirediameter; and determining an initial tension between the pair ofrollers, and a maximum tension between the pair of rollers, in view ofthe wire data.
 16. A method of adjusting a wire feed, comprising:feeding a wire through a feeding mechanism that applies a force to thewire; measuring a fed speed of the wire after it exits from the feedingmechanism; deciding whether to adjust the force applied to the wire. 17.A method of adjusting a wire feed, comprising: feeding a wire through afeeding mechanism that applies a force to the wire; measuring a fedspeed of the wire after it exits from the feeding mechanism; comparing adriven speed of the wire with the fed speed of the wire; and decidingwhether to adjust the force applied to the wire.
 18. The method ofadjusting a wire feed recited in claim 17, further comprisingcalculating the driven speed of the wire inside the feeding mechanism.19. The method of adjusting a wire feed recited in claim 17, furthercomprising increasing the force applied to the wire when the drivenspeed of the wire is greater than the fed speed of the wire.
 20. Themethod of adjusting a wire feed recited in claim 17, further comprising:entering wire data via a user interface, wherein the wire data comprisesa wire diameter; and determining an initial force applied to the wire,and a maximum force applied to the wire, in view of the wire data. 21.An automatic wire feed adjuster, comprising a control circuit thatdecides whether to instruct a tension controller to adjust a tensionbetween a pair of rollers in a feeding mechanism that feeds a wiretherebetween.
 22. The automatic wire feed adjuster recited in claim 21,wherein the control circuit decides whether to instruct the tensioncontroller to adjust the tension by comparing a driven speed of the wiredetermined from the pair of rollers with a fed speed of the wiremeasured on the wire.
 23. An automatic wire feed adjuster, comprising atension controller that adjusts a tension between a pair of rollers in afeeding mechanism that feeds a wire therebetween in view of a comparisonof a driven speed of the wire determined from the pair of rollers withthe fed speed of the wire measured on the wire.